Bearings



9, 1966 c. H. T. PAN ETAL 3,265,452

BEARINGS Filed May 4, 19 5 l 4 Sheets-Sheet 5 United States Patent O3,265,452 BEARENGS Coda H. T. Pan, Latham, and Elis B. Arwas,Schenectay,

N.Y,, assignors to Mechanical Technology Incorporated, Latham, N.Y., acorporation of New York Filed May 4, 1965, Ser. No. 456,888 1 Claim.(Cl. 308-9) This application is a continuation-in-p art of applicationSerial No. 217,373, filed August 16, 1962, now abandoned.

This invention rel a tes to selflac-t ing, gas lnbricated journalbearings for spherically configured journals.

An example of the use of spherically configured journals received withinhem i-spherically configured and complemental bearings is that of theoompressor shaft. The compressor sh aft rot-ate s at very high speedsand presents problems relating to oapacities of the bearing for highthrust or axial load, Combined radial and thrust load andself-alignment.

This invention and 'the several emhodinents thereof solve the problemsof high thrust load capacity, combined radiai and thr-ust load capacityand self alignment capacity.

This object and other objects of the invention should be appreciatedfrom the detailed specification taken in conjunction With the drawings,in which like reference numerals refer to similar parts throughout theseveral views, in which:

FIG. 1 is' a View, partly in section, of one enrbodiment of theinvention;

FIG. 2 is a tragmentary top pl an View taken along the line 2-2 of FIG.1;

FIG. 3 is a view, partly in section, of another embodiment ot theinvention.

FIG. 4 is a view, .part'ly in section, of another embodiment of theinvention;

FIG. 5 is a View, p artly in section, ment of the invention;

FIG. 6 is a view, p artly in section, ment of the invention;

FIG. 7 is a firagmentary top plan view taken along the line 7- 7 of FIG.6;

FIG. 8 is a fragmentary view of a journal and bearing of a feature ofthe invention;

FIG. 9 is a View, partly in section, of another embodiment of theinvention wherein .the journal is generated as a frustu m of a rightCircular cone received within a complementally configured hearing;

-F IG. 10 is a View, partl'y in section, of 'another embodiment of theinvention wherein the journal is generated 'as a right circular conereceived within a complement-ally configured bearing;

FIG. 11 is a View, partly in section, of another embodiment of theinvention wherein the journal is of ellipsoidal configuration and isreceived wit-hin a complementally configured bearing;

FIG. 12 is a View, p artly in section ot another embodiment of theinvention wherein the journal is of ellip soida-l configuration and isreceived Within a complementally configured bearing.

In FIG. 1 is shown a journal 1 ot substantial-ly spherical configurationrotating in bearing 3 of hemispherical complemental configuration. InFIG. 1 and in the other views the journal as viewed from the top rot-ates in a counterclock wise direction.

Shown more idiscernibly in FIG. '2 are the spiraled grooves 7 formed inthe bearing surface and Which communicate with port 5 formed through thepio-lar region of bearing 3 and in symmetn'cal alignment with the centerline of 'bearing 3. The grooves 7 are in symmet-ical -arrangement on thebearing surtace.

The 'bottom portion of the bearing where port 5 is located is referredto in the description of the embodiof another embo di- Otf anotherembodi- 3,2%,452 Patented August 9, 1966 ICC,

ments of the invention as the pol ar region. The upper portion of thebearing is refer-red to in the description of the embodiments of theinvention as the equat orial region. In :this connection, and in thedrawings, reference numeral 25 generally refers to the polar region andreference numeral 27 generally refers to the equatori al region, andwhich regions are designated in all the embodiments of the invention.Furthermore, what is: meant by the termino logy-region-is the thin gapvolume that exists in the embodiments of the invention between thejournals and their respective bearing surfaces. .The region is filledwith gas and it is there that the pressures are generated.

In FIG. 3, journal 1 is shown received in bearing 9 which has spiraledgrooves 11 formed in the bearing surface commencing from the equatoriatlregion of the hearing and symmetrically arranged thereon. Grooves 11 areshown more discernibly in FIG. 7.

In FIG. 4, journal 1 is shown received in bearing 13 which has spiraledgrooves 11 formed in the bearing surface commencing from the equatorialregion Otf the bearing and symnetrically arranged thereon. Grooves 11communicate with a manifold 15. The manifold is a continuous groeweformed on the bearing sutnfiace and in symmetrical arrangement thereon.

In FIG. 5, journal 1 is shown received in bearing 17 which has spira ledgroowes 7 fiormed in the hearing surface commencing from communicationWith port 5 in the polar region and symmetrical-ly arranged thereon.Grooves 7 communicate with maniiold 15 for-med on the be aring surfiaceand in symmetrical arrangement thereon.

In FIG. 6, journal 1 is shown received in bearing 19. Shown morediscernibly in FIG. 7 are spiraled grooves 7 formed in the bearingsurface commen-cing from communication with port 5 in the polar regionand Symmetrically arranged thereon. The spiraled groo-ves -11 :formed inthe bearing surface commencing from the equatorial region of the bearingand syimmetrically arranged thereon are shown. Grooves 7 and 11communicate with manifold 15.

In FIG. 8, the journal 1 is shown rotating relative to the groove 271formed in hearing 23. 'I'he Significance depicted is to show the flow ofgas induced in groove 21 by rotation of journal 1. Groove 21 may beeither one of gro'oves 7 or 1 1.

The depth of grooves 7 and two to four times the clearance between thejournal and bearing. 'I`he groowes 7 and 11 and manifold 15 are depictedas squareshaped in cross-section. The grooves 7 and 11 and 'manifold 15may be cut to be semicircular in cross-'section, The particularconfiguration of the groo-ves in cross-section will depend upon themethod ntilized to form same.

It is within the concept of this invention to form the grooving geometryof grooves 7 and 11 and manifold 15 on the journal `1 instead of on thebearing. In this situation the growing will he in the opposite sense.

It should 'be appreciated that the spiraled grooves douhle as a stepthrust bearing and :as a viscous pump to feed the journal portion Olfthe bearing. Parameters of bearing ge'ometry that are Variable foroptimum design reqnirements of the bearing are the dep th and width ofthe grom/e s, the spiral anglo of the grooves and the length of thegrooves.. The bearing ,will be: stitf from the geometry of the spiralgrowing and the viscous pomp [feature of same 'will create positivepressures increasing the cap acities of the bearing. By stiffnes's ismeant that 'any dimensional changes in the separation between thesurfaces of the journal and hearing automatically induce correspondingchanges in the pressures in the aft'ected regions, efBec-tuated in thisin sitance hy the grooving .geometry, Which oppose the dimensionalchange separation. By viscous purnp or viscous pump feature is meant 11is made varying firom the tan-gential velocity between the journal andthe gas, ie., the relative movement of the journal tangential to the gassuch movement shears the gas and shear stresses are generated. Theseshear stresses are induced because of the Viscosity of the gas and aretransformed into the positive .pressures which carry the load. Since thegas or fluid is sheared to eect the positive pressure generation andsince this phenomenon is predicated upon the viscosity otf the gas orfiuid, the resulting effect of positive pressure generation from thecooperatin-g structure and gas or fiuid is referred .to as the viscouspump feature.

In FIG. 1 flow of gas Will be induced from port 5, as indicated, intothe spira-led grooves 7 into the polar region of the bearing therebycreating positive pressures in this region. 'Ilhe thrust capacity of the'bearing will be increased measurably contrasted to the negligiblethrust capacity of a hernispherical bearing without the groowinggeometry.

In FIG. 3 flow of gas will be induced from the equatorial region ofspiraled grooves 141 and exit through port 5. Positive pressures will becreated in the equatorial region. Higher pressures can be generated bythe equatorial purnpin g grooves than by the polar purnping groovesbecause the Linear speed is higher in the equatorial region and thegrooving geometry over the length of the grooved region is more nearlyconstant in the equatorial region.

The equatorial grooves will reduce the attitude angle, provide greaterstability and increase the threshold speed of the journal at which theprecession phenomenon is encountered. A more involved discussion o f theprecession phenomenon may be discerned in the application of Elie B.Arwas and Beno Ste-rnlicht entitled Bearings and filed August 2, 1962,Serial No. 214,316, now abandoned.

Al ong the spiraled grooves 7 and 11 the positive pressures generatedwill rise and fall. The effect of the manifold 15 will be to decreasethe amplitude of the :generated pressures and to make the amp l-itude ofthe generated pressures more nearly uniform. Accordingly Where greaterthr-ust capacity in the bearing is needed, the manifold would beeliminated.

Therefore it should be apprecia ted that the greatest amplitude ofpositive pressures will be generated in the bearing having bothequatorial and polar gro'oving geometry. The gas flow induced from boththe port 5 through grooves 7 and from the equatorial region throughgrooves 11 will be in opposition to one another building up greater gaspressures. The disadvan tage of using equatomial and polar groovinggeometry is the higher cost to manufacture the bearing and a secondarydisadvantage ot the stagnant region between the equatorial and p-olargroovings preventing the cooling effect of air flow.

I-t should be appreciated that the utility ot the inventi-on is notrestricted to the Vertical or horizontal disposition of the journalshatt.

Another advantage of the invention is the ali-gnment capacity of a shafthaving journals at each end received in hemispherical bearings. Thelines of centers ot the journal and bearings Would indicate that thelines of centers are parallel to each other. In bearings for cylindricaljournals the alignment of the bearings and journal must be maintainedwith olearances in the magnitude of one mil. In the spherical journalreceived in the hemispherical bearings the alignment factor is not ascritical because of the capacity for sel f-alignment.

It is within the concept ot this invention to utilize a journalgenerated either as a frustum of a right circular cone or a rightcircular cone received within a complementally configured bearing havingthe species of grooving geometry utilized with the hemisphericalbearing. An advantage of the eonical journal and cromplementa'l bearingis the lesser degree of clearance that would be permitted to be adjustedbetween journal and bearing.

Also within the concept of the invention is the use of an ellipsoidaljournal and complemental bearing with the specles of grooving geometryutilized with the hemispherical bearing.

In FIG. 9 is shown a journal configured as a frustum of a rightcircul-ar cone received within its complementally configured bearing 31.Bearing 3 1 has .port 5, and grooving 7 and 11 pmvided in the p'o'larand equatorial regions, respectively.

In FIG. 10 is shown a journal 33 configured as a right circular conereceived within its complementally configured :bearing 3 5. Bearing 35is provided with grooving 7 and 11 in the p o-lat and equatorialregions, respectively. It should he noted that an inlet port is notnecessary in this embodiment.

In FIG. 11 is shown a journal 3 7 OLf ellipso idal configurationreceived Within its complement-allly configured bearing 39. Bearing 39had port 5, and grooving 7 and 11 provided in the polar and equatorialregions, respective'ly.

In FIG. 12 is shown journal 41 of another ellipsoidal configurationreceived Within its complementally confiured bearing 43. Bearing 43 hasport S, and groovin-g 7 and 11 provided in the polar and equatorialregions, respectively.

Not sho wn in the embodiments of FIGS. 9, 10, 11 and 12 are themanifolds 15 utilized in the prior embodiments 'with either the grooving7 or grooving 11, or as a common manifold for both grooving 7 and 11. Itshould be appreciated, m oreover, that 'with respect to each of theernbodiments Off FIGS. 9, 10, 11 and 12, grooving 7 and 11 and manifold15 can be utilized as in the case of the prior embodiments.

Having thusly described our invention, we claim: A Combined journal andthrust bearing comp rising,

a stationary member having a top surface and a semispherical cavityformed therein,

a rotating member designed with surfaces complementary to said cavityand positioned for r-otation therein,

a shaft integrally formed with said rota-ting member,

an air gap between said members,

an opening comprising a gas p assa geway formed in the bottom ot thestationary member cavity for permitting the flow of gas lutbrioantthrough the air s p, grooves of a skewed geo met-ry on said Stationerymember cavity walls for stifiiening said bearing and generating positivepressures therein upon relative motion of said staitionary and 'otatingmembers,

said grooves being 'located between said opening in the cavity andthe',top surface of the stationary member and occupying less than thetotal distance therebetween; and

said grooves having a Width substantially less than the land widthbetween adj-acent grooves.

References Cited by the Examiner UNITED STATES PATENTS 2,495,745 1/1950Litton 308-159 2,722,463 11/1955 Sh'aw et al. 308-172 2,8995243 8/ 1959`Acterman.

2,9l5,902 12/1959 Bmgger.

2,937,804 5/1960 Reiner et al. 308-9 3,016,273 1/1962 Benoit.

3,06 3,041 1 1/ 1962 Quade et al.

3,154,353 10/1964 Haringx et al.

DAVID J. WILLIAMOWSKY, Primary Exam'ner.

FRANK SUSKO, Exam'ner.

